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Qt on Raspberry PiJeff Tranter

Integrated Computer Solutions (ICS)

Qt Developer Days 2012

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Agenda

• What is the Raspberry Pi?• Raspberry Pi Foundation• Hardware• Software

• QtonPi Distribution• QtonPi Device Program• Qt 4 on Raspberry Pi• Qt 5 on Raspberry Pi

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Agenda (continued)

• Input Devices - Mouse, Keyboard• Output Devices and Touchscreen• Major Competitors• Misc. Issues

• Areas Of Future Development• Demo• References• Summary

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What is the Raspberry Pi?

"The lack of programmable hardware for children – the sort of hardware we used to have in the 1980s – is undermining the supply of eighteen year olds who know how to program, so that's a problem for universities, and then it's undermining the supply of 21 year olds who know how to program, and that's causing problems for industry."

- Co-founder Eben Upton in 2012

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Raspberry Pi Foundation

• Non profit British charity• Promotes basic computer science in schools• Small: day to day work done by one full-time paid

employee and volunteers• Manufacturing and sales licensed to distributors:

Element 14 and RS

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What is the Raspberry Pi?

• Project originally started in 2006

• Eventually decided on ARM architecture

• Alpha boards Aug 2011

• Beta boards Dec 2011

• Sales launched February 2012

• First batch of 10,000 boards in Mar 2012

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What is the Raspberry Pi?

• Two licensed manufacturers/distributors

• Initially unable to keep up with orders

• Two million people registered interest in pre-orders

• Backlog now down to a few weeks

• Most manufacturing now done in the UK

• As of Nov 2012 Sony plant in Wales making 16,000 boards per week

• Farnell has shipped 429,000 boards as of end of Nov (RS probably similar)

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What is the Raspberry Pi?

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What's With the Name?

• Nostalgia: a number of early home computers had "fruit" names, e.g. Apple, Apricot, Tangerine

• PI is from "Python Interpreter", the official programming language for the Raspberry Pi

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Hardware

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Hardware

• Credit card sized computer• CPU: Broadcom BCM2835 SOC• 700MHz ARM11 with floating point• Videocore 4 GPU capable of BluRay quality 1080p30

video using H.264 at 40MBits/s• OpenGL ES2.0 and OpenVG• SD card for mass storage (can also use USB after

booting)• Model A: 256MB RAM, 1 USB port (not yet shipping)• Model B: 512MB* RAM, 2 USB ports, Ethernet

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Hardware

• Composite and HDMI video out• Sound output over HDMI and 3.5mm audio jack; can

use USB microphone for input• Header with GPIO ports• Powered by 5V over micro USB (2.5W/3.5W. Could

use battery, i.e. 4 AA cells. Power by USB port not recommended.)

• No RTC (gets time from network)• Memory not expandable

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Hardware

• Retail price US$25 (Model A) / US$35 (Model B)• Board only: typically add HDMI monitor, SD card, USB

keyboard and mouse, power supply• Some users may use television and second hand

keyboard/mouse to save on cost• Hardware schematics available

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Input Devices - Mouse, Keyboard

• USB mouse and keyboard supported• Can use (powered) hub if more than two USB devices

needed

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Output Devices and Touchscreen

• HDMI and composite video out• Can use DVI or VGA monitor with adaptor• Standard touch screen monitors with HDMI should

work out of box if they emulate a USB mouse• Chalkboard Electronics has compatible 10 inch

touchscreen with HDMI to LVDS interface board• Dell 2220 touch screen monitor (needs modified

kernel)

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Other Hardware

• GPIO, serial, SPI, I2C, JTAG ports• brought out on 26-pin connector P1• use caution if used directly as no protection from

overvoltage, etc.• MIPI CSI-2 (Camera Serial Interface) on connector S5• DSI (Display Serial Interface) on connector S2 for

driving LCD (no drivers currently)

• Rev 2 board makes some small changes

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Other Hardware

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Other Hardware

• Official camera module:– Approx. $25– 5 MP images and video– Attaches to CSI port via ribbon cable

• GPIO expansion boards: AdaFruit Pi Cobbler, AdaFruit Pi Plate, GertBoard

• LCD displays• Third party cases

• Many more to come

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Software

• Linux-based• recommended distro is Debian-based Raspbian

"Wheezy" (uses hardware FP)• Several other Linux distros supported• GPU code was proprietary but open sourced in Oct• Other operating systems: RISC OS (Acorn), Android,

BSD, Plan 9, AROS, Open WebOS, etc.

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Software

• Currently aimed mostly at developers• Preferred language for educational apps is Python• Will eventually include applications like games and

development tools for kids including BASIC, Python• Unlikely to Run Windows 8 (needs newer ARM CPU)• Can't run Windows apps using WINE since not x86

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Raspbian Distribution

• Currently the preferred distribution• Based on upcoming Debian 7.0 “Wheezy” release• Optimized for Raspberry Pi hardware• LXDE - Lightweight X11 Desktop Environment

• Uses hardware floating point in ARM chip• Over 35,000 software packages• http://www.raspbian.org/

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QtonPi Distribution

• Qt 5-focused distribution• SDK (Qt Creator) with development tools• SD card image• Fedora based

• No longer maintained, Qt 5 packages are now in Debian Wheezy beta and soon in Raspbian

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Other Distributions

• AdaFruit Occidentalis distribution for teaching electronics

• AdaFruit WebIDE: browser based IDE that runs on desktops

• ARCH Linux ARM• Soft-float Debian Wheezy

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QtonPi Device program

• 400 boards ordered by Nokia and partners like ICS in late 2011

• Allocated to Qt developers who were qualified with project ideas

• Delivery was delayed by move to using licensed hardware distributors

• Shipped to developers and partners in August 2012

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Qt 4 on Raspberry Pi

• Packages available on Debian Wheezy beta and Raspbian

• Doesn't make use of graphics hardware acceleration (no OpenGL)

• Runs okay in my experience• Focus of development is on Qt 5 where Scene Graph

pushes more work to GPU

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Qt Mobility (Qt 4)

• Qt add-on used by some applications• Not available as a package• Was not ported to Raspberry Pi per se• Builds from source without changes

• Some modules are not applicable (e.g. phone-specific)• Use latest source from git as the 1.2 release is getting

old and has some compile issues• In Qt 5 Mobility becomes optional Qt 5 modules

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Qt 5 on Raspberry Pi

• Nokia sponsored work (QtonPi) since late 2011

• Can use Wayland and hardware accelerated cursor

• Uses GStreamer for multimedia

• H.264 only free HD video format supported on Pi due to licensing issues

• Hardware similar to some Nokia phones?

• Packages currently in Debian Wheezy beta, moving to Raspbian

• Packaging of QtMultimedia and QtWebKit being worked on

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Qt 5 on Raspberry Pi

• See qt-project.org Wiki

• Bakeqtpi script to cross-compile Qt 5 on desktop

• Qt Creator can be used to build (cross-compile) and deploy

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EGLFS

• Qt 5 on Raspberry Pi normally uses EGLFS back end

• Uses OpenGL/ES for rendering

• Runs full screen, no window manager, one application instance, does not use X11

• Wayland compositor backend can play nicely with X11 and window managers while still using OpenGL/ES

• xcb backend for X11 currently has no OpenGL support (needed for Qt Quick 2)

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Raspberry Pi Competitors

• For embedded development• BeagleBoard (more expensive)• Arduino (simpler OS)• VIA APC (Android)

• Many others coming...

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Misc Issues

• Wheezy includes "omxplayer" video player application• Foundation sells licenses for commercial codecs: VC-1

(Microsoft) and MPEG-2• RAM is shared between CPU and GPU. Can adjust

how it is split (See Wiki and raspi-config program)• Compiling on the Pi is slow. Can cross-compile on a

Linux desktop. See Wiki for details.• QEMU emulator to emulate Raspberry Pi on Windows

or Linux desktop• Hardware compatibility issues with some SD cards

(should be mostly resolved now)

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Misc Issues

• Overclocking/overvoltage possible (up to 1 GHz)• For more filesystem storage you can connect USB

flash or hard drive• Can use USB dongle for Wi-Fi if it has a suitable driver• Official book: Raspberry Pi User Guide• Free monthly magazine: The MagPi• Summer 2012 coding contest

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Areas Of Future Development

• Port of Android 4.0 (already demoed)• Model A (manufacturing started)• Educational/consumer version with case, power

supply, keyboard, etc.• Third party add-ons like cases, touch screens,

expansion boards

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Demo

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References

• http://www.raspberrypi.org/• http://qt-project.org/wiki/Qt-RaspberryPi• http://qt-project.org/wiki/RaspberryPi• http://qt-project.org/wiki/RaspberryPi_Beginners_guide

• https://gitorious.org/bakeqtpi• http://www.raspbian.org

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Summary

• Raspberry Pi is an extremely low cost computer that can be used for embedded Qt 5 development.

• Good reference platform for Qt 5 with Qt Quick 2 (QML scene graph)

• Needs volunteers to help develop the platform and applications.

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The End

Thank you very much for attending!

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Q&A

• Questions?